<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*行内元素垂直对齐方式:top middle bottom baseline基线*/
        img{
            /*vertical-align: top;*/
            vertical-align: middle;
            /*vertical-align: bottom;*/
            /*vertical-align: baseline;*/
            border-radius: 50px;
        }
    </style>
</head>
<body>
<input type="text"><img src="../b.jpg" style="width: 50px" alt="">
</body>
</html>